One of the most important factors of tuning a carburetor – is having the proper fuel pressure to feed your carb.
Unfortunately, many folks are running fuel pumps (mechanical or electric) that push too much pressure for street use, causing a multitude of headaches, like…
- Overfilling the fuel bowl
- Rich running
- Hard starting
- Poor gas mileage
- Damage the needle/seat
The fix is easy – install either a pump with the proper pressure – or plumb in a regulator. As a bonus, adding a return line will improve your pump efficiency, lower fuel temperature, and significantly reduce vaporization.
And the answer to how much pressure you should be running – for a street carburetor… see below. It’s probably less than you expect, and while you (and I) are used to seeing pressures as high as 7PSI, that pressure is not best for street-performance.
Best Fuel Pressure for Street Carburetors:
- Holley 5-6 PSI
- Edelbrock 4-5 PSI
- Stromberg WW 3.5-4 PSI